Sunday, December 19, 2010

Tank Progress Continues...

It's been a busy week, but I've still managed to make a lot of progress on my little Sherman tank. First off, I had to rip down an ipe plank and make the last sixteen track shoes I needed. Here I am turning the ends on the lathe:

Once I had all the parts I needed, I lined them up on the table saw and pulled out the jig:

Then it was time to pre-drill, glue, and screw all of the parts together. There were 58 outer track plates and 58 inners, so I had to turn down 116 ends, fit them with 116 stainless bushings, then drill 232 holes and drive 232 screws, all while sandwiching a strip of conveyor belting and a thich coat of epoxy in between. It was a long afternoon:

In the end, this was the resulting track:

I also made a lot of progress on the transmission. I learned a lot along the way. Among the lessons: I can't weld worth a damn. Also, the grinder absolves the welder of many sins:

After I'd cleaned up the welds (most of which looked like some kind of moon rocks) I mounted the shafts, gears, and belts:

Now I just need to attach the idler levers, mount the whole assembly under the driver's seat, connect a drive belt to the engine, and run chain to the drive shafts at the forward end of the tank. Then I'll just need to cut out my drive sprockets, hang the tracks, and start tearing up the back field.

Here's the finalized design for the drive sprockets:

It turns out that a nine-tooth sprocket is the largest I can reasonably fit under the sponsons on either side of the tank.